Melodius pure is an underrated deck.
I had put this together for fun, and I started using it in Master 3, and it has been surprisingly good. The ceiling doesn't compare to the nonsense made by Fiendsmith and his gang of exaggerations.
But it is very consistent, and also resilient to handtraps. Furthermore, the fact that monsters cannot be targeted by effects, nor can they be destroyed by battle or effects, creates very funny situations.
The fact that it can also carry 18 slots for non-engine is incredible, especially since Orange Arklight is at 3, so it can use it very well.
Anyway, it is a deck that I honestly didn't expect anything from, but it has delivered a lot. And as for you, which deck did you put together unpretentiously, but that has performed well in your climb in the ranked?